checkNotModified needs to consider HEAD as well

Issue: SPR-11317
(cherry picked from commit 17cc63e)

Author: jhoeller

spring-web/src/main/java/org/springframework/web/context/request/ServletWebRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -47,6 +47,8 @@ public class ServletWebRequest extends ServletRequestAttributes implements Nativ
 
 	private static final String METHOD_GET = "GET";
 
+	private static final String METHOD_HEAD = "HEAD";
+
 
 	private HttpServletResponse response;
 
@@ -155,7 +157,7 @@ public boolean checkNotModified(long lastModifiedTimestamp) {
 			long ifModifiedSince = getRequest().getDateHeader(HEADER_IF_MODIFIED_SINCE);
 			this.notModified = (ifModifiedSince >= (lastModifiedTimestamp / 1000 * 1000));
 			if (this.response != null) {
-				if (this.notModified && METHOD_GET.equals(getRequest().getMethod())) {
+				if (this.notModified && supportsNotModifiedStatus()) {
 					this.response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
 				}
 				else {
@@ -172,7 +174,7 @@ public boolean checkNotModified(String eTag) {
 			String ifNoneMatch = getRequest().getHeader(HEADER_IF_NONE_MATCH);
 			this.notModified = eTag.equals(ifNoneMatch);
 			if (this.response != null) {
-				if (this.notModified && METHOD_GET.equals(getRequest().getMethod())) {
+				if (this.notModified && supportsNotModifiedStatus()) {
 					this.response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
 				}
 				else {
@@ -181,7 +183,11 @@ public boolean checkNotModified(String eTag) {
 			}
 		}
 		return this.notModified;
+	}
 
+	private boolean supportsNotModifiedStatus() {
+		String method = getRequest().getMethod();
+		return (METHOD_GET.equals(method) || METHOD_HEAD.equals(method));
 	}
 
 	public boolean isNotModified() {

spring-web/src/test/java/org/springframework/web/context/request/ServletWebRequestTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -37,6 +37,7 @@
 
 /**
  * @author Juergen Hoeller
+ * @author Markus Malkusch
  * @since 26.07.2006
  */
 public class ServletWebRequestTests {
@@ -116,7 +117,7 @@ public void decoratedNativeRequest() {
 	}
 
 	@Test
-	public void checkNotModifiedTimeStamp() {
+	public void checkNotModifiedTimeStampForGET() {
 		long currentTime = new Date().getTime();
 		servletRequest.setMethod("GET");
 		servletRequest.addHeader("If-Modified-Since", currentTime);
@@ -127,7 +128,7 @@ public void checkNotModifiedTimeStamp() {
 	}
 
 	@Test
-	public void checkModifiedTimeStamp() {
+	public void checkModifiedTimeStampForGET() {
 		long currentTime = new Date().getTime();
 		long oneMinuteAgo  = currentTime - (1000 * 60);
 		servletRequest.setMethod("GET");
@@ -140,7 +141,7 @@ public void checkModifiedTimeStamp() {
 	}
 
 	@Test
-	public void checkNotModifiedETag() {
+	public void checkNotModifiedETagForGET() {
 		String eTag = "\"Foo\"";
 		servletRequest.setMethod("GET");
 		servletRequest.addHeader("If-None-Match", eTag );
@@ -151,7 +152,7 @@ public void checkNotModifiedETag() {
 	}
 
 	@Test
-	public void checkModifiedETag() {
+	public void checkModifiedETagForGET() {
 		String currentETag = "\"Foo\"";
 		String oldEtag = "Bar";
 		servletRequest.setMethod("GET");
@@ -163,4 +164,52 @@ public void checkModifiedETag() {
 		assertEquals(currentETag, servletResponse.getHeader("ETag"));
 	}
 
+	@Test
+	public void checkNotModifiedTimeStampForHEAD() {
+		long currentTime = new Date().getTime();
+		servletRequest.setMethod("HEAD");
+		servletRequest.addHeader("If-Modified-Since", currentTime);
+
+		request.checkNotModified(currentTime);
+
+		assertEquals(304, servletResponse.getStatus());
+	}
+
+	@Test
+	public void checkModifiedTimeStampForHEAD() {
+		long currentTime = new Date().getTime();
+		long oneMinuteAgo  = currentTime - (1000 * 60);
+		servletRequest.setMethod("HEAD");
+		servletRequest.addHeader("If-Modified-Since", oneMinuteAgo);
+
+		request.checkNotModified(currentTime);
+
+		assertEquals(200, servletResponse.getStatus());
+		assertEquals(""+currentTime, servletResponse.getHeader("Last-Modified"));
+	}
+
+	@Test
+	public void checkNotModifiedETagForHEAD() {
+		String eTag = "\"Foo\"";
+		servletRequest.setMethod("HEAD");
+		servletRequest.addHeader("If-None-Match", eTag );
+
+		request.checkNotModified(eTag);
+
+		assertEquals(304, servletResponse.getStatus());
+	}
+
+	@Test
+	public void checkModifiedETagForHEAD() {
+		String currentETag = "\"Foo\"";
+		String oldEtag = "Bar";
+		servletRequest.setMethod("HEAD");
+		servletRequest.addHeader("If-None-Match", oldEtag);
+
+		request.checkNotModified(currentETag);
+
+		assertEquals(200, servletResponse.getStatus());
+		assertEquals(currentETag, servletResponse.getHeader("ETag"));
+	}
+
 }